Muffler



' 1,618,876 Feb. 22,1927. A: HAMPTON ET AL MUFFLER Filed April 2'7, 1926 2 Sheets-Sheet 1 I N VEN TORS:

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' Feb. 22, 1927.

1,618,876 A. E. HAMPTON ET AL MUFFLER Filed April 27, 192.6 2"She et 5-Shqgia 2 Z IC? J w! mzssrs:

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' Patented .r'eb. '22, 192 7.

4- UNITED STATES v PATENT OFFICE.

Antwan n. HAMPTON, or PITTSTOWN, AND CHARLES s. MARSHALL, or nar'rrsrown,

, NEW. JERSEY,

MUFFLER.

This invention relates to mufiiers for silencing the exhaust noise of internal combustion engines.

The present day mufller, as it' is well known, retains a large volume of gases therein. This is due to its construction which provides large spaces through which the exhaust gases pass during the silencing action. Should the ignition system fail to explode one or more charges of' fresh gas in the engine cylinders, these charges will be ex pglled into the muflier and the muffler will filled with the fresh gas. When the ignition' system functions again, the hot exploded into the muflier, i te the fresh gases therein and explode t em with a violent force, causing serious damage to the mufller. It

' ofttimes happens that onl the interior of the muflier 1s dama ed. hisis not readily detected and usual y obstructs the passage for thegases, thereby causing high back pressure on the en e. As a result, the engine, though it be in excellent working coni dition, fails to produce the usual power and this causes much trqu'ble and inconvenience.

The objects of ourinvention are to pro-' vide a mufiler which will to a large extent, .soaovercome the danger of damage to the muffler;jwhich is highly efficient in its silencing action, and which, when the engine runs at slow speed, will have little silencing effect on the exhaust gases so as to enable one to hear and detect any irregularity in the order of firing of the engine cylinders.

These objects, and other advantageous ends which will be described hereinafter, we attain in the ,following manner, reference be}? ,had to the accompanying drawings in Figure 1 is a side elevation of a mufller constructed in accordance with our invention 3 Figure 2 an end view of the muflier shown in Figure 1 looking from the left,

Figure 3 a. like view of the mufller looking from the right of Figure 1,

Figure 4' a central longitudinal sectional view taken on line 44 of Figure 3,

Figure 5 a transverse sectional view taken on line 5-5 of Figure 4, and Fi re 6 a like view taken on line 66 of Figure 4. Referring to the draw ngs, 1 indicates an gases, expelled from the cylinders Application filed April 27, 1926. Serial no. 104,893.

outershell, 2 an inner shell disposed concentrically thereto, 3 a head on the rear end of the shells for keeping them properly spaced, 4: a head on the front end of the inner shell, 5 a head on the front end of the outer shell, heads 4 and 5 being separate parts to facilitate assembling, 6 tie'bolts passing through the heads and within the shells for fastening the heads to the shells, an internal combustion engine connected with the front head, and 8 a manifold connected with the exhaust pipe, which changes pulsating exhaust gases coming from the exhaust pipe to a continuous stream and thus effects a silencing action 'on the exhaust noises.

The manifold consists of a unit 9, for convenience called discharge unit, and a series of units 10 hereinafter called suction units. The discharge unit 9 is provided with a discharge conduit 11 spaced from and surrounding a central conduit 12. The exhaust gases pass throughthe space between conduits 11 and 12, and issue from the dis charge unit through outlet 13 into the inner shell 2, from which they are sucked by the suction units 10. 4

The suction units, which are four in number, each consists of a suction conduit 14 spaced from and surrounding a central conduit 15, aligned with central conduit 12, and an inlet 16 communicating with the suction conduit '14. The exhaust gases as they are sucked from shell 2 enter. inlet 16 and pass through the space between suction conduit 14 and central conduit 15. We have shown four suction units 10 but any desired number may be used to meet different requirements; We preferably provide a pressure equalizing chamber 17 between the discharge unit 9 and the adjacent suction unit 10 and also between the suction units 10. These chambers act to store the high pressure pulsating volumes of exhaust gases, and release them at a less and more uniform pressure to the adjacent suction unit 10. The manifold 8 is mounted in the rear head 3 and is fastened to the front head 5 by a bolt 18 passing through a boss 19 on head ,5. This bolt also passes through exhaust pipe and fastens it to the muflier.

The inner shell has an opening 20 adjacent the rear end thereof to allow excess exhaust gases discharged therein to pass to theouter shell. The gases then pass out from ,the

7 an exhaust pipe of outer shell through an opening 21 in a pipe 22 and then pass through this pipe out of the mufller. Pipe 22 also serves to connect the heads to the shells by nuts 23 similar to tie bolts 6. A bracket 24 is attached to the rear head 3 for securing the muffler to the vehicle.

In operation the exhaust gases coming from pipe 7 in successive pulsating volumes pass partly through central conduit 12 and the remainder pass through the space between said conduit and the discharge conduit 11. The gases passing through conduit 12 enter the first pressure equalizing chamber 17 and then pass through the central conduit 15 of the suction unit. The gases issue from this conduit 15 in a jet within suction conduit 14 and create a region of low pressure due to the high velocity of the gases. The gases discharged through outlet 13 into the inner shell rush through inlet 16 into the region of low pressure in suction conduit 14 as indicated by the arrows. The gases then pass into the second pressure equalizing chamber 17 and from there into the central conduit 15 of the next suction unitlO. The action of the gases through this next unit and the succeeding ones is similar to the action just described in the'preceding unit 10. The gases are thusly discharged from the discharge unit 9, and sucked through outlets 16 into each of the suction units 10 to the region of low pressure in the central conduit 14. This action of the gases changes the successive gas pulsations comlng from the exhaust pipe 7, to a continuous stream which issues quietly from the flared outlet end 25. of the manifold. The equalizing chambers 17 aid in changing these successive gas pulsations of non-uniform velocities and pressures, to a continuous gas stream of practically uniform velocity and pressure. When an excessive amount of gases comes from discharge pipe 7, they may pass out from the inner shell through the opening 20 to the outer shell and then through the opening 21 into the pipe 22 and out of the muffler as indicated by the arrows.

\Vhen the engine is operated at slow speed with the vehicle idle to ascertain the regularity of the order of firing of the cylinders,

* the gases coming from discharge pipe 7 are of such slow speed that little suction is created in the suction units 10 and conseuently little silencing action is produced on t e gases, thus enabling one to hear and detect any irregularity in the order of firing of the cylinders.

The muffler above described is practically free of the danger of harmful explosions caused by the misfiring of the engine cylinders, because little or practicallynone of the fresh gas remains in the inner shell of the mufller, owing to the constant suction of the suction units 10.

While we have described our invention as taking a particular form, it will be understood that the various parts may be changed Without departing from the spirit thereof, and hence we do not limit ourselves to the precise construction set forth, but consider that we are at liberty to make such changes and alterations as fairly come within the scope of the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is l. A mufller including a casin and a manifold passing through the casing; the manifold having a longitudinal central passage therethrough, a discharge conduit com.- municating with the casing, a series of suction conduits communicating with the casing with the inner ends of said suction conduits surrounding but spaced from walls of the central passage, and an expansion chamber formed in the central passage between each two suction conduits.

2. A muffler including a casing and a manifold passing through the casing, said manifold having a discharge conduit communicating with the casing; a central conduit within and spaced from the discharge conduit; a second central conduit communicating with the first mentioned central conduit, and a suction conduit surrounding the last mentioned central conduit and spaced therefrom, whereb gases passing through the manifold wi l partly discharge through the discharge conduit into the casing and partly pass through the central conduits to create a suction at t e suction conduit for drawing the gases fromthe casing back into said conduit.

3. A mufller including an inner shell, an outer shell surrounding the inner shell and communicating therewith and with the outer air, and a manifold assing through the inner shell; the mani old having a longitudinal central passage therethrough, a. d18- charge conduit communicating with the inner shell and a series of suction conduits communicating with the inner shell with the inner ends of said suction conduits surrounding but spaced from walls of the central passage.

4. A mufiler including an inner shell; an outer shell surroundin the inner shell and communicating therewith, and a manifold passing through the inner shell, said manifold having a conduit for discharging gases into the inner shell, suction conduits for drawingthe gases from the inner shell back into said manifold, and a conduit leading from the outer shell to the outer air.

5. A mufller including an open ended inner shell having an opening in its wall; an open ended outer shell surrounding the inner shell; a head mounted on the rear end of the shells; a head mounted on the front end of the inner shell; a head mounted on the front end of the outer shell means passing through the heads and within the shells for fastening cured to the heads and passing within the the heads to the shells; a manifold passing outer shell for discharging ases therefrom. within the inner shell; said manifold hav- In testimony whereof-we ave signed our 10 ing means for discharging gases into the names to this specification.

5 inner shell. and means for causing suction A a for drawing the gases from" the inner shell ABIJAH E. HAMPTON.

back into said manifold, and a conduit se- CHARLES S. MARSHALL. 

